The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.
Nutrients are essential in the growth and development of crops. Crops absorb nutrients such as nitrogen, phosphorus, and potassium in the surrounding soil to facilitate crop growth. Different types of crops have different requirements for each nutrient. When a crop is unable to meet its nutrient needs, the crop suffers. For example, a lack of nitrogen may lead to destruction of a crop's leaves. Additionally, once the nitrogen concentration in a plant decreases below a critical threshold, photosynthesis and dry matter accumulation is negatively impacted. An end result is that the yield of a crop which does not receive enough nutrients is decreased.
While nutrients in the soil are important to plant growth, it is difficult to determine when soil lacks one or more nutrients without performing nutrient tests. Additionally, the impact of a specific nutrient application is not readily apparent. For example, an application of forty pounds per acre of nitrogen at one time may result in a net increase of ten pounds of nitrogen per acre available to a crop due to nitrogen loss through a variety of factors and low transmission rates to the crop. The same application of forty pounds per acre of nitrogen at another time may result in the majority of the applied nitrogen being available to a crop. Without an understanding of all of the factors that affect whether a crop will receive the nitrogen added to a field, nitrogen application tends to be relatively blind. A farmer may apply nitrogen to a field at specific stages in a crop's development or when the crop appears to be suffering from a lack of nitrogen. Such applications of nitrogen are inefficient as they either involve wasting nitrogen or not adding enough nitrogen to satisfy the needs of a plant. Additionally, nitrogen lost to the field through leaching may create environmental problems when the nitrogen joins the watershed.
The amount of each nutrient available to a crop tends to be dependent on a wide variety of factors. For example, moisture content, soil type, and soil temperature affect the flow of nitrogen through the soil, the lateral transmission of nitrogen to the roots of a plant, and the loss of nitrogen through denitrification, volatilization, and leaching. Additionally, the uptake of nutrients by a crop varies from crop to crop and varies based on the stage of development of a specific crop. Furthermore, different layers of soil have may have different compositions, different temperatures, and different moisture contents. Thus, the transmission of nutrients through the soil may vary from soil layer to soil layer.
There is a need for a system which receives data about a particular field, ranging from soil data to weather data, and models the availability of nutrients in the particular field based on the received data. A few difficulties arise in the context of modeling nutrient availability based on the wide variety of factors. A first difficulty in modeling nutrient availability is determining nutrient availability in the future, such that intelligent nutrient application decisions can be made before problems begin to arise. While current soil samples may be used to determine nutrient availability at a given time, nutrient availability in the future is difficult to model without future temperature and precipitation data. A second difficulty in modeling nutrient availability is the computation expense of modeling factors that affect nutrient availability. For example, methods of modeling moisture content in soil tend to be extremely computationally expensive, requiring an iterative scheme to solve a non-linear differential equation, or computational inexpensive but extremely inaccurate.